This project will use data from the American Hospital Association Annual Survey of Hospitals, a survey of managed care organizations, the State Inpatient Database (SID), and several additional data sources to compare safety net and non-safety net hospitals on a variety of dimensions of performance. Specifically, the project will assess differential effects of health care market structure on safety net and non-safety net hospitals with regard to participation in hospital systems and managed care networks, financial performance, service offerings, and provision of charity care.. The project's methodologic contributions will consist of exploring alternative approaches for identifying and classifying safety net hospitals, and using hospital financial data from selected states and the discharge data from the SID to develop and validate measures of charity care based on discharge data.